(a) Field of the Invention
The present invention relates to an improved method of treating a waste water with activated sludge. More specifically, an appropriate amount of sea water is added to the waste water in the method.
(B) Description of the Prior Art
Activated sludge has been used for treating various types of waste water. It has been known that the activated-sludge method has such disadvantages as a requirement of a long time for coagulation and separation of the activated sludge in a settling tank, and lowering of coagulation and sedimentation depending on conditions of the activated sludge. In order to overcome these disadvantages, use of various types of coagulants has been proposed. However, available coagulants composed mainly of inorganic or organic compounds are not satisfactory, because of increased accumulation of metals (such as Fe, Al, etc.) in the activated sludge, difficulty of storage, and so on.
It is an object of this invention, therefore, to provide an improved method for treating a waste water with activated sludge.